%------------------------------------------------------------------------
% Draws a representation of a lens at the position and angle specified.
%
% SYNTAX: [handle,texthandle,pos,rotpos]
%              =lensplot(d <,t,x,y,theta,lambda,label,labelpos,suppress>);
%
% INPUT ARGUMENTS:
% d         = diameter of the lens. The lens radius of curvature is assumed 
%             to be essentially infinite (1e30).
%             d can also be passed as a 2-element vector d=[diameter,radius],
%             where the first element is the lens diameter and the second
%             is the radius of curvature of the lens surface. 
% t         = additional lens thickness (same units as the diameter)
% x,y       = x,y - position offset, default=0,0.
% theta     = rotation of optic axis counterclockwise relative to x-axis,
%             defaul=0
% lambda    = wavelength, default=1064 nm
% label     = string with which to label the lens, default is ''.
% labelpos  = 0 to put label at bottom, 1 to put label at top, default 0
% suppress  = set to 1 to suppress plotting, default 0.
%
% OUTPUT ARGUMENTS:
% handle    = handle of the trace plotted
% texthandle= handle of the text label if supplied (otherwise -1)
% pos       = 2xn matrix. Second row is lens face height, first row is
%             the corresponding position along the optic axis, measured
%             from the point at which q is specified.
% rotpos    = 2xn matrix. x,y coordinates of the lens trace,
%             first row corresponds to x coord's, second row to y coord's.
%
% Last Modified: Dec. 10, 2003 by Andri M. Gretarsson.
%
%-------------------------------------------------------------------------
% SYNTAX: [handle,texthandle,pos,rotpos]
%              =lensplot(d <,t,x,y,theta,lambda,label,labelpos,suppress>);
%-------------------------------------------------------------------------

function [handle,texthandle]=lensplot(d,varargin)

if size(d,2)>1, Rlens=d(2); else Rlens=1e30; end
if nargin>=2, t=varargin{1}; else t=0; end
if nargin>=3, x=varargin{2}; else x=0; end
if nargin>=4, y=varargin{3}; else y=0; end
if nargin>=5, theta=varargin{4}*pi/180; else theta=0; end
if nargin>=6, lambda=varargin{5}; else lambda=1064e-9; end
if nargin>=7, label=varargin{6}; else label=''; end
if nargin>=8, labelpos=varargin{7}; else labelpos=0; end
if nargin>=9, suppress=varargin{8}; else suppress=0; end

lensheight=d(1)/2;
phimax=asin(lensheight/Rlens);
phi=-phimax:phimax/100:phimax;
if Rlens>=0
    curvethickness=abs(Rlens-Rlens*cos(phimax));
    xleftside=Rlens*(cos(phimax)-cos(phi))+curvethickness;
    xrightside=-Rlens*(cos(phimax)-cos(phi))+curvethickness+t;
    xtop=[max(xleftside),min(xrightside)]; 
    xbottom=[max(xleftside),min(xrightside)];
    xcenter=t/2+curvethickness;
else
    curvethickness=abs(Rlens-Rlens*cos(phimax));
    xleftside=Rlens*(cos(phimax)-cos(phi));
    xrightside=-Rlens*(cos(phimax)-cos(phi))+t+2*curvethickness;
    xtop=[min(xleftside),max(xrightside)]; 
    xbottom=[min(xleftside),max(xrightside)];
    xcenter=curvethickness+t/2;
end
yleftside=Rlens*sin(phi);
yrightside=yleftside;

rightside=[xrightside;yrightside];
leftside=[xleftside;yleftside];
top=[xtop;[max(yleftside),max(yrightside)]];
bottom=[xbottom;[min(yleftside),min(yrightside)]];

rotmat=[[cos(theta), -sin(theta)];[sin(theta), cos(theta)]];
rotrightside=rotmat*(rightside-[ones(size(rightside(1,:)))*xcenter;zeros(size(rightside(2,:)))]);
rotleftside=rotmat*(leftside-[ones(size(rightside(1,:)))*xcenter;zeros(size(rightside(2,:)))]);
rottop=rotmat*(top-[ones(size(top(1,:)))*xcenter;zeros(size(top(2,:)))]);
rotbottom=rotmat*(bottom-[ones(size(bottom(1,:)))*xcenter;zeros(size(bottom(2,:)))]);

rotrightside(1,:)=rotrightside(1,:)+x+xcenter;
rotrightside(2,:)=rotrightside(2,:)+y;
rotleftside(1,:)=rotleftside(1,:)+x+xcenter;
rotleftside(2,:)=rotleftside(2,:)+y;
rottop(1,:)=rottop(1,:)+x+xcenter;
rottop(2,:)=rottop(2,:)+y;
rotbottom(1,:)=rotbottom(1,:)+x+xcenter;
rotbottom(2,:)=rotbottom(2,:)+y;

switch labelpos
case 2,
    augmentedlabel=['  ',label];
    xtextpos=max(rotrightside(1,:));
    ytextpos=( min(rotrightside(2,:)) + max(rotrightside(2,:)) )/2;
case 0,
    augmentedlabel=strvcat(' ',label); %#ok<VCAT>
    xtextpos=max(rotrightside(1,:));
    ytextpos=min(rotrightside(2,:));
case 1,
    augmentedlabel=strvcat(label,' '); %#ok<VCAT>
    xtextpos=max(rotrightside(1,:));
    ytextpos=max(rotrightside(2,:));
end

if suppress~=1
    handle=plot(rotrightside(1,:),rotrightside(2,:),'k-',...
        rotleftside(1,:),rotleftside(2,:),'k-',...
        rottop(1,:),rottop(2,:),'k-',...
        rotbottom(1,:),rotbottom(2,:),'k-');
    if ~isempty(label)
        texthandle=text(xtextpos,ytextpos,augmentedlabel);
    else
        texthandle=-1;
    end
end